This looks a lot like a project being developed by Bryan Roberts (IIRC) in Australia, that New Scientist covered about fifteen years ago. He was using a gyrocopter-like structure (he called it a gyromill) to keep the devices up in the air, and with an intent to be much higher up than these things seem to be aimed at, but the principle remains the same (tethered, high enough to gain some consistency of wind).

Can't find the NS link, but this provides some more info: http://www.abc.net.au/science/news/enviro/EnviroRepublish_18...

[Edit: add url, fix historical reference.]